Hi Sakari,
On 11/24/2016 03:23 PM, Sakari Ailus wrote:
Hi Jacek,
On Wed, Oct 12, 2016 at 04:35:16PM +0200, Jacek Anaszewski wrote:
Make struct v4l2_subdev capable of aggregating v4l2-ctrl-bindings -
media device configuration entries. Added are also functions for
validating support for the control on given media entity and checking
whether a v4l2-ctrl-binding has been defined for a media entity.
I still don't think this belongs here.
I think I told you about the generic pipeline configuration library I worked
on years ago; unfortunately it was left on prototype stage. Still, what I
realised was that something very similar is needed in that library ---
associating information to the representation of the media entities (or the
V4L2 sub-devices) in user space that has got nothing to do with the devices
themselves.
We could have e.g. a list of key--value pairs where the key is a pointer
provided by the user (i.e. application, another library) that could be
associated with the value. That would avoid having explicit information on
that in the struct media_entity itself.
An quicker alternative would be to manage a list of controls e.g. in the
plugin itself and store the media entity where they're implemented in that
list, with the control value.
We are not interested in media entity -> control value relation but
but media entity -> control id. The value is an arbitrary choice of
userspace. Binding's task is to route the ctrl ioctl to a desired
pipeline entity if more than one supports same control.
Effectively we'd need a list of controls as a keys and entities
as values. The list should be allocated dynamically as it would
make no sense to keep keys for all v4l2 controls if only few bindings
are defined.
Best regards,
Jacek Anaszewski
Cc Laurent as well.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
utils/media-ctl/libv4l2subdev.c | 32 ++++++++++++++++++++++++++++++++
utils/media-ctl/v4l2subdev.h | 19 +++++++++++++++++++
2 files changed, 51 insertions(+)
diff --git a/utils/media-ctl/libv4l2subdev.c b/utils/media-ctl/libv4l2subdev.c
index c3439d7..4f8ee7f 100644
--- a/utils/media-ctl/libv4l2subdev.c
+++ b/utils/media-ctl/libv4l2subdev.c
@@ -50,7 +50,15 @@ int v4l2_subdev_create(struct media_entity *entity)
entity->sd->fd = -1;
+ entity->sd->v4l2_ctrl_bindings = malloc(sizeof(__u32));
+ if (entity->sd->v4l2_ctrl_bindings == NULL)
+ goto err_v4l2_ctrl_bindings_alloc;
+
return 0;
+
+err_v4l2_ctrl_bindings_alloc:
+ free(entity->sd);
+ return -ENOMEM;
}
int v4l2_subdev_create_opened(struct media_entity *entity, int fd)
@@ -102,6 +110,7 @@ void v4l2_subdev_close(struct media_entity *entity)
if (entity->sd->fd_owner)
close(entity->sd->fd);
+ free(entity->sd->v4l2_ctrl_bindings);
free(entity->sd);
}
@@ -884,3 +893,26 @@ const enum v4l2_mbus_pixelcode *v4l2_subdev_pixelcode_list(unsigned int *length)
return mbus_codes;
}
+
+int v4l2_subdev_supports_v4l2_ctrl(struct media_device *media,
+ struct media_entity *entity,
+ __u32 ctrl_id)
+{
+ struct v4l2_queryctrl queryctrl = {};
+ int ret;
+
+ ret = v4l2_subdev_open(entity);
+ if (ret < 0)
+ return ret;
+
+ queryctrl.id = ctrl_id;
+
+ ret = ioctl(entity->sd->fd, VIDIOC_QUERYCTRL, &queryctrl);
+ if (ret < 0)
+ return ret;
+
+ media_dbg(media, "Validated control \"%s\" (0x%8.8x) on entity %s\n",
+ queryctrl.name, queryctrl.id, entity->info.name);
+
+ return 0;
+}
diff --git a/utils/media-ctl/v4l2subdev.h b/utils/media-ctl/v4l2subdev.h
index 011fab1..4dee6b1 100644
--- a/utils/media-ctl/v4l2subdev.h
+++ b/utils/media-ctl/v4l2subdev.h
@@ -26,10 +26,14 @@
struct media_device;
struct media_entity;
+struct media_device;
struct v4l2_subdev {
int fd;
unsigned int fd_owner:1;
+
+ __u32 *v4l2_ctrl_bindings;
+ unsigned int num_v4l2_ctrl_bindings;
};
/**
@@ -314,4 +318,19 @@ enum v4l2_field v4l2_subdev_string_to_field(const char *string);
const enum v4l2_mbus_pixelcode *v4l2_subdev_pixelcode_list(
unsigned int *length);
+/**
+ * @brief Check if sub-device supports given v4l2 control
+ * @param media - media device.
+ * @param entity - media entity.
+ * @param ctrl_id - id of the v4l2 control to check.
+ *
+ * Verify if the sub-device associated with given media entity
+ * supports v4l2-control with given ctrl_id.
+ *
+ * @return 1 if the control is supported, 0 otherwise.
+ */
+int v4l2_subdev_supports_v4l2_ctrl(struct media_device *device,
+ struct media_entity *entity,
+ __u32 ctrl_id);
+
#endif
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